Botoi Readability API vs Flesch-Kincaid Readability & Grade Level Analyzer

Botoi Readability API analyzes English text and returns Flesch-Kincaid Grade, Flesch Reading Ease, Gunning Fog, and underlying counts. A request sends a required text string to POST /v1/text/readability and receives JSON. Flesch Reading Ease scores run from 0 to 100, with higher values indicating easier reading; Gunning Fog estimates the years of formal education needed. The formulas and syllable heuristics are calibrated for English, so grade mapping is not meaningful for other languages. Botoi recommends sending at least 100 words because short samples can produce unstable scores. Suggested uses include enforcing plain-language standards, reviewing legal or medical drafts, refining blog posts for SEO, and comparing writing across authors. Examples are provided in cURL, JavaScript, TypeScript, Python, and Go. The Free plan is free and lists 1,000 requests per day and 10 per minute; the endpoint page separately states five requests per minute for its free tier. Starter costs $9 a month. Requests above a per-minute or daily cap receive HTTP 429, and daily limits reset at midnight UTC.

Flesch-Kincaid Readability & Grade Level Analyzer is a free web calculator for estimating how readable English text may be. It calculates Flesch reading ease and Flesch-Kincaid grade level from sentence, word, and syllable counts. Results include both scores alongside the word, sentence, and estimated syllable counts, with a button to copy them. The page also offers sentence analysis and clarity recommendations, framing its scores as a quick, rough proxy and suggesting shorter sentences and more common words as ways to improve them.

Syllables are estimated by counting vowel groups rather than looking up pronunciations, so silent vowels, unusual spellings, and non-standard pronunciations can throw off the count. The formulas address sentence length and syllable mechanics; they do not assess logic, jargon, tone, or overall clarity. No account is required. Veomark says most of its tools run in the browser and core inputs are not uploaded to its servers, though Google Analytics 4 may use cookies or similar technologies. The calculator lists no integrations. Its plan is free. For privacy questions, Veomark directs visitors to contact the domain registrar or hosting account holder listed for veomark.com.